''Iku-Turso'' was a 500-tonne

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

that served in the

Finnish Navy The Finnish Navy ( fi, Merivoimat, sv, Marinen) is one of the branches of the Finnish Defence Forces. The navy employs 2,300 people and about 4,300 conscripts are trained each year. Finnish Navy vessels are given the ship prefix "FNS", short for ...

during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. It was launched in May 1931 and was named after a mythological Finnish sea monster, Iku-Turso. It was built by the

Crichton-Vulcan Crichton-Vulcan is an abandoned shipyard in Turku, Finland, that once formed the cornerstone of the Finnish shipbuilding industry. The shipyard is best known for the World War II coastal defence ships and submarines it produced. Shipbuild ...

shipyard in Turku according to a project developed by NV Ingenieurskantoor voor Scheepsbouw, "IvS", and was scrapped in 1953.

Combat history

Winter War

On 7 December ''Iku-Turso'' was sortied to intercept the Soviet freighter ''Ivan Papanin'' sailing from Stockholm. The submarine was informed of the departure time of the target and the likely route and so ''Iku-Turso'' patrolled in the international waters off Sandhamn and Svenska Högarne during the night. Unidentified patrol boats harassed the submarine and forced it to dive and by the time ''Iku-Turso'' was able to reach periscope depth there were no freighters in sight. ''Ivan Papanin'' had passed the area few hours earlier and likely having been warned of the presence of the Finnish submarine, it had altered its course to evade ''Iku-Turso''. In late December 1941 ''Iku-Turso'' patrolled for a couple of days off Liepāja but did not encounter any targets the rules of engagements would have allowed the submarine to attack. In January 1941 ''Iku-Turso'' patrolled four days off Saaremaa and Hiiumaa but without any luck.

Continuation War

On 22 June 1941 ''Iku-Turso'' laid 20 mines north of the island of Mohni/Ekholm. A further 20 mines were laid at Ruuskeri SE from Gogland on 24 June and 18 mines to south of Vaindloo on 26 June after which further minelaying operations were postponed. ''Iku-Turso'' laid 18 already loaded mines on 11 July of the coast of

Estonia Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, a ...

east of Mohni. On 30 July ''Iku-Turso'' along with ''Vetehinen'' were sortied to intercept a Soviet convoy moving to and from the besieged base of Hanko. The submarines saw the convoy but were unable to maneuver to attack position. In December 1941, after the Soviets had evacuated Hanko, ''Iku-Turso'' was docked for the winter. Though ''Iku-Turso'' had not had much chance of using its torpedoes, the experiences from other Finnish subs were that the Italian torpedoes used (Finnish designation T/40) were unreliable. During 1942, ''Iku-Turso'' was upgraded with new 12-hydrophone listening arrays and equipped with a depth charge rack capable of carrying 4 depth charges. The submarine was further modified by streamlining the tower and moving the 20 mm gun up to the tower. On 27 October 1942, after unsuccessfully attacking a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

with the 20 mm Madsen cannon in poor visibility, ''Iku-Turso'' later came across and torpedoed another Soviet Shchuka-class submarine. After the torpedo impacted, the target disappeared. On the impact site, the Finnish submarine located a large oil spill with even more oil still rising to the surface. The sunken submarine's identity has later been contested as several Soviet submarines of Shchuka class were lost at that time in the area but the most likely candidates are either ''Shch-320'' or perhaps even more likely ''Shch-308'' as some Russian sources claim that ''Shch-320'' had been sunk by a mine earlier that month and that the initial unsuccessful attack by ''Iku-Turso'' had been against ''Shch-307''. On 30 July 1944 ''Iku-Turso'' attempted to attack a convoy targeting a tug but failed to reach firing position. On 24 August 1944 ''Iku-Turso'' ran into an obstacle — apparently an anti-submarine net - but was able to get loose. A mine which had been attached to the obstacle exploded but caused only light damage to the submarine.

Notes and references

{{DEFAULTSORT:Iku-Turso Vetehinen-class submarines Ships built in Turku 1931 ships World War II submarines of Finland